anonymizer/test/anonymizer.test.ts

import { describe, it, expect, vi } from 'vitest';
import { Anonymizer, AnonymizationError, presets, type LlmProvider } from '../src/index.js';

/** An LLM provider that is configured but always fails → forces the regex fallback. */
const failingLlm = (overrides: Partial<LlmProvider> = {}): LlmProvider => ({
  isConfigured: () => true,
  anonymize: vi.fn().mockRejectedValue(new Error('LLM_NOT_CONFIGURED')),
  anonymizeBatch: vi.fn().mockRejectedValue(new Error('LLM_NOT_CONFIGURED')),
  ...overrides,
});

describe('Anonymizer (Swiss preset)', () => {
  const svc = new Anonymizer({ llm: failingLlm(), patterns: presets.swiss });

  it('skips anonymization (no LLM call) when there is no PII', async () => {
    const llm = failingLlm();
    const s = new Anonymizer({ llm, patterns: presets.swiss });
    const r = await s.anonymize('Explique la différence entre INNER JOIN et LEFT JOIN');
    expect(r.mapping).toEqual({});
    expect(r.anon).toContain('INNER JOIN');
    expect(llm.anonymize).not.toHaveBeenCalled();
  });

  it('falls back to regex for structured PII (email/phone/AVS)', async () => {
    const r = await svc.anonymize('Contact: jean@exemple.ch, +41 79 123 45 67, AVS 756.1234.5678.90');
    expect(r.anon).not.toContain('jean@exemple.ch');
    expect(r.anon).not.toContain('756.1234.5678.90');
    expect(Object.values(r.mapping)).toContain('jean@exemple.ch');
    expect(svc.deanonymize(r.anon, r.mapping)).toContain('jean@exemple.ch');
  });

  it('deanonymizes a placeholder split across stream tokens (critical)', () => {
    const mapping = { '[PER_1.NOM:M]': 'Alain JACCARD' };
    const d = svc.makeStreamDeanonymizer(mapping);
    let out = '';
    out += d.push('Bonjour [PER_');
    out += d.push('1.NOM');
    out += d.push(':M], ravi');
    out += d.flush();
    expect(out).toBe('Bonjour Alain JACCARD, ravi');
    expect(out).not.toContain('[PER_');
  });

  it('streams plain text through unchanged', () => {
    const d = svc.makeStreamDeanonymizer({});
    expect(d.push('Un INNER JOIN ') + d.push('retourne...') + d.flush()).toBe('Un INNER JOIN retourne...');
  });

  describe('anonymizeChunks', () => {
    it('PII-free chunks → no LLM call, returned as-is', async () => {
      const llm = failingLlm();
      const s = new Anonymizer({ llm, patterns: presets.swiss });
      const r = await s.anonymizeChunks(['Un INNER JOIN combine deux tables.'], { mapping: {} });
      expect(llm.anonymizeBatch).not.toHaveBeenCalled();
      expect(r.anon[0]).toContain('INNER JOIN');
      expect(r.mapping).toEqual({});
    });

    it('reuses the question placeholder for the same person (deterministic, no LLM)', async () => {
      const llm = failingLlm();
      const s = new Anonymizer({ llm, patterns: presets.swiss });
      const seed = { '[PER_1.NOM:M]': 'Alain JACCARD' };
      const r = await s.anonymizeChunks(['Le dossier de Alain JACCARD est complet.'], { mapping: seed });
      expect(llm.anonymizeBatch).not.toHaveBeenCalled();
      expect(r.anon[0]).toContain('[PER_1.NOM:M]');
      expect(r.anon[0]).not.toContain('Alain JACCARD');
      expect(r.mapping).toEqual(seed);
    });

    it('renumbers a NEW person that collides with the question placeholder', async () => {
      const anonymizeBatch = vi.fn().mockResolvedValue({
        segments: ['[PER_1.NOM:M] a signé.'],
        mapping: { '[PER_1.NOM:M]': 'Bob Martin' },
        legend: { PER: 'Personne', NOM: 'Nom de famille', M: 'Masculin' },
      });
      const s = new Anonymizer({ llm: failingLlm({ anonymizeBatch }), patterns: presets.swiss });
      const seed = { '[PER_1.NOM:M]': 'Alain JACCARD' };
      const r = await s.anonymizeChunks(['Bob Martin a signé.'], { mapping: seed });
      expect(anonymizeBatch).toHaveBeenCalledTimes(1);
      expect(r.anon[0]).toContain('[PER_2.NOM:M]');
      expect(r.mapping['[PER_1.NOM:M]']).toBe('Alain JACCARD');
      expect(r.mapping['[PER_2.NOM:M]']).toBe('Bob Martin');
      // legend covers the abbreviations used in the anonymized chunk
      expect(r.legend).toMatchObject({ PER: 'Personne', NOM: 'Nom de famille', M: 'Masculin' });
    });

    it('falls back to regex (structured ids) when the LLM is unavailable', async () => {
      const s = new Anonymizer({ llm: failingLlm(), patterns: presets.swiss });
      const r = await s.anonymizeChunks(['Contact : jean@exemple.ch'], { mapping: {} });
      expect(r.anon[0]).not.toContain('jean@exemple.ch');
      expect(Object.values(r.mapping)).toContain('jean@exemple.ch');
    });
  });

  describe('regex-only mode (no LLM provider)', () => {
    const s = new Anonymizer({ patterns: presets.swiss });

    it('still anonymizes structured PII without any provider', async () => {
      const r = await s.anonymize('Écris à jean@exemple.ch');
      expect(r.anon).not.toContain('jean@exemple.ch');
      expect(Object.values(r.mapping)).toContain('jean@exemple.ch');
    });

    it('leaves a bare proper name untouched (no LLM to catch it)', async () => {
      const r = await s.anonymize('Alain Jaccard a réussi');
      // The name-hint flags it, but with no LLM the regex fallback finds no structured id.
      expect(r.anon).toContain('Alain Jaccard');
      expect(r.mapping).toEqual({});
    });
  });

  describe('configurable presets', () => {
    it('generic preset anonymizes an IPv4 address', async () => {
      const s = new Anonymizer({ patterns: presets.generic });
      const r = await s.anonymize('Serveur 192.168.1.42 indisponible');
      expect(r.anon).not.toContain('192.168.1.42');
      expect(Object.values(r.mapping)).toContain('192.168.1.42');
    });

    it('accepts a fully custom pattern set', async () => {
      const s = new Anonymizer({ patterns: [{ tag: 'TICKET', re: /\bJIRA-\d+\b/g }] });
      const r = await s.anonymize('Voir JIRA-123');
      expect(r.anon).toContain('[TICKET_1]');
      expect(r.mapping['[TICKET_1]']).toBe('JIRA-123');
    });
  });

  describe('legend', () => {
    it('the regex fallback produces a French legend from tag meanings', async () => {
      const s = new Anonymizer({ patterns: presets.swiss });
      const r = await s.anonymize('Écris à jean@exemple.ch');
      expect(r.legend).toEqual({ EMAIL: 'Adresse e-mail' });
    });

    it('backfills a missing legend entry from the built-in default (LLM omitted it)', async () => {
      const anonymize = vi.fn().mockResolvedValue({
        anon: 'Dossier de [PER_1.NOM:M]',
        mapping: { '[PER_1.NOM:M]': 'Alain Jaccard' },
        legend: {}, // model returned no legend
      });
      const s = new Anonymizer({ llm: failingLlm({ anonymize }), patterns: presets.swiss });
      const r = await s.anonymize('Dossier de Alain Jaccard');
      expect(r.legend).toEqual({ PER: 'Personne', NOM: 'Nom de famille', M: 'Masculin' });
    });

    it('a custom tag with a meaning surfaces it in the legend', async () => {
      const s = new Anonymizer({
        patterns: [{ tag: 'TICKET', re: /\bJIRA-\d+\b/g, meaning: 'Ticket de suivi' }],
      });
      const r = await s.anonymize('Voir JIRA-123');
      expect(r.legend).toEqual({ TICKET: 'Ticket de suivi' });
    });
  });

  describe('fail-closed (optional fallback)', () => {
    it('throws if neither an LLM nor patterns are provided', () => {
      expect(() => new Anonymizer({})).toThrowError(AnonymizationError);
    });

    it('LLM-only: a provider failure throws AnonymizationError with the cause', async () => {
      const cause = new Error('LLM_HTTP_500');
      const s = new Anonymizer({ llm: failingLlm({ anonymize: vi.fn().mockRejectedValue(cause) }) });
      await expect(s.anonymize('Contact: jean@exemple.ch')).rejects.toBeInstanceOf(AnonymizationError);
      await expect(s.anonymize('Contact: jean@exemple.ch')).rejects.toMatchObject({ cause });
    });

    it('LLM-only: bypasses the pre-filter so PII-free text still hits the provider', async () => {
      const anonymize = vi.fn().mockResolvedValue({ anon: 'INNER JOIN', mapping: {}, legend: {} });
      const s = new Anonymizer({ llm: failingLlm({ anonymize }) });
      await s.anonymize('Explique INNER JOIN'); // no structured PII, no name hint
      expect(anonymize).toHaveBeenCalledTimes(1);
    });

    it('LLM-only: anonymizeChunks rejects with AnonymizationError on provider failure', async () => {
      const s = new Anonymizer({ llm: failingLlm() }); // anonymizeBatch rejects
      await expect(s.anonymizeChunks(['Bob Martin a signé.'], { mapping: {} })).rejects.toBeInstanceOf(
        AnonymizationError,
      );
    });
  });
});